userret.h revision 1.1 
1/*	$NetBSD: userret.h,v 1.1 2005/07/10 17:02:19 christos Exp $ */
2
3/*
4 * Copyright (c) 1996
5 *	The President and Fellows of Harvard College. All rights reserved.
6 * Copyright (c) 1992, 1993
7 *	The Regents of the University of California.  All rights reserved.
8 *
9 * This software was developed by the Computer Systems Engineering group
10 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
11 * contributed to Berkeley.
12 *
13 * All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Lawrence Berkeley Laboratory.
17 *	This product includes software developed by Harvard University.
18 *
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
21 * are met:
22 * 1. Redistributions of source code must retain the above copyright
23 *    notice, this list of conditions and the following disclaimer.
24 * 2. Redistributions in binary form must reproduce the above copyright
25 *    notice, this list of conditions and the following disclaimer in the
26 *    documentation and/or other materials provided with the distribution.
27 * 3. All advertising materials mentioning features or use of this software
28 *    must display the following acknowledgement:
29 *	This product includes software developed by the University of
30 *	California, Berkeley and its contributors.
31 *	This product includes software developed by Harvard University.
32 * 4. Neither the name of the University nor the names of its contributors
33 *    may be used to endorse or promote products derived from this software
34 *    without specific prior written permission.
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
37 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
40 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
44 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
45 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46 * SUCH DAMAGE.
47 *
48 *	@(#)trap.c	8.4 (Berkeley) 9/23/93
49 */
50
51#include <sys/userret.h>
52
53static __inline void userret(struct lwp *, int,  u_quad_t);
54static __inline void share_fpu(struct lwp *, struct trapframe *);
55
56
57/*
58 * Define the code needed before returning to user mode, for
59 * trap, mem_access_fault, and syscall.
60 */
61static __inline void
62userret(struct lwp *l, int pc, u_quad_t oticks)
63{
64	struct proc *p = l->l_proc;
65	int sig;
66	mi_userret(l);
67
68	if (cpuinfo.want_ast) {
69		cpuinfo.want_ast = 0;
70		if (p->p_flag & P_OWEUPC) {
71			p->p_flag &= ~P_OWEUPC;
72			ADDUPROF(p);
73		}
74	}
75	if (cpuinfo.want_resched) {
76		/*
77		 * We are being preempted.
78		 */
79		preempt(0);
80		while ((sig = CURSIG(l)) != 0)
81			postsig(sig);
82	}
83
84	/*
85	 * If profiling, charge recent system time to the trapped pc.
86	 */
87	if (p->p_flag & P_PROFIL)
88		addupc_task(p, pc, (int)(p->p_sticks - oticks));
89
90	curcpu()->ci_schedstate.spc_curpriority = l->l_priority;
91}
92
93/*
94 * If someone stole the FPU while we were away, do not enable it
95 * on return.  This is not done in userret() above as it must follow
96 * the ktrsysret() in syscall().  Actually, it is likely that the
97 * ktrsysret should occur before the call to userret.
98 */
99static __inline void share_fpu(struct lwp *l, struct trapframe *tf)
100{
101	if ((tf->tf_psr & PSR_EF) != 0 && cpuinfo.fplwp != l)
102		tf->tf_psr &= ~PSR_EF;
103}
104